Refrigerant reciprocating compressor



y 28, 1958 s. A. PARKER 3,385,515

REFRIGERANT RECIPROCATING COMPRESSOR Filed Oct. 17, 1966 3 Sheets-Sheet1 FFEnJ.

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REFRIGERANT RECIPROCATING COMPRESSOR Filed Oct. 17, 1966 s Sheets-SheetUnited States Patent 3,385,515 REFRTGERANT RECHPRQQATHNG CQMPRESSORSidney A. Parker, Fort Worth, Tex., assigner to Lennon industries, Inc.,a corporation of Iowa Filed Oct. 17, 1966, Ser. No. 537,005 12 Claims.(Cl. 230-232) This invention relates to a refrigerant reciprocatingcompressor and, more particularly, to an improved crankcase constructionfor such compressors.

Heretofore it has been customary to form compressor crankcases ofcastings, and in many cases to cast a supporting sleeve for the statorof an electric driving motor integral with the crankcase. One suchconstruction embodying a cast crankcase structure is disclosed, forexample, in Patent No. 3,073,515.

A cast crankcase structure is subject to a number of disadvantages.Among these are the cost of castings, the weight due to the necessityfor relatively thick walls, the necessity for and difliculty ofmachining a large number of surfaces and the dilliculty of removing allthe sand from the casting and particularly from the suction annulus anddischarge annulus within the casting.

It is accordingly one of the objects of the present invention to providea refrigerant reciprocating compressor in which the crankcase is formedof sheet metal stampings secure-d together by hydrogen brazing orchemical adhesives to define a complete crankcase assembly.

According to a feature of the invention, a valve housin g is permanentlysecured in the crankcase assembly by brazing and one or more cylinderinserts and the crankshaft for reciprocating the pistons are assembledin the crankcase later.

Another object of the invention is to provide a refrigerantreciprocating compressor in which the crankcase has permanently securedthereto a sleeve for supporting the stator of a driving motor and inwhich substantially all of the parts are formed of sheet metal.

Among the several advantages of forming a crankcase of sheet metal partsare that the walls of the assembly may be made much thinner and lighterdue to the greater strength of sheet metal over cast iron or castaluminum, the necessity for machining after assembly is eliminated andthe necessity for cleaning is also eliminated. These several featuresnot only result in a better crankcase structure, but also one which isless expensive.

The above and other objects and features of the invention will be morereadily apparent from the following description when read in connectionwith the accompanying drawings, in which:

FIG. 1 is an axial section with parts in elevation of a completecompressor assembly embodying the invention;

FIG. 2 is an axial section through the crankcase assemy;

FIG. 3 is a top view of the assembly of FIG. 2;

FIG. 4 is a partial section on the line 4-4 of FIG. 2;

FIG. 5 is an axial section through a modified crankcase assembly; and

FIG. 6 is a bottom view of the modified crankcase assembly takengenerally along line 66 of FIG. 5.

A complete compressor embodying the invention as shown in FIG. 1comprises a gas-tight housing formed by an upper shell 10 and a lowershell 11 which are cupshaped and. are joined by weldin or the like. Thebottom of the lower shell is preferably formed with three or moreoutwardly cupped projections 12 which are secured to a base or mountingplate 13 by which the compressor assembly may be mounted in any desiredposition.

A crankcase embodying the present invention and indicated generally at14 is mounted within the housing. For this purpose the crankcasepreferably carries a plurality 3,335,515 Patented May 28, 1968 ofdownwardly extending legs or pins 15 at its bottom corresponding innumber and spacing to the projections 12. Springs 16 surround the pins15 and sleeves 15a, made from nylon or like material and are seated inthe hollow projections 12 to locate and support the crankcase assemblyproperly within the housing. The housing is provided with a suction gasinlet connection 17 and with a dis charge gas conduit 18.

Electric power for operating the motor is supplied through a control boxor terminal box 19 mounted on the side of the housing and carrying leadsas indicated at 21 which extend through the housing wall in sealedrelationship and through a conduit 22 into the upper part of thecrankcase assembly.

The crankcase assembly per se, as best seen in FIGS. 2-4, is made up ofthree concentric sleeves 23, 24 and 255. The sleeves are confinedbetween upper and lower annular plate members to which they arepermanently secured as by hydrogen brazing, or chemical adhesives. Theupper plate member, as shown, is formed of two annular plates 26 and 27which are connected in faceto-face relationship and which are formedwith registering arcuate openings 28 therethrough for the passage ofsuction gas as will be described more fully hereinafter. The upper plate26 extends beyond the oute sleeve 23 and is formed with an upwardlyturned flange 2% which, as best seen in FIG. 1, lies closely adjacent tothe inner wall of the housing. The flange Z9 is formed with a series ofopenings in its periphery which receive resilient bumpers, such as therubber buttons 5 shown in FIG. 1 to bear against the inner wall of thehousing, thereby to assist in supporting the crankcase assembly in thehousing. The flange 29 may cooperate with the sleeve surrounding themotor to define an oil reservoir for holding oil pumped from the sumpduring compressor operation. Suitable passage means (not shown) may beprovided to communicate the crankshaft pump means with the reservoir.

At their inner edges, the plates 26 and 27 are flared in oppositedirections as indicated at 31 and 32, respectively. A tubular bearinghousing 33 fits into the opening defined by the flanges 31 and 32 and isprelerably formed with an external shoulder as indicated at 34 to reston the flange 31. The bearing housing 33, which may be made frompowdered metal, is permanently secured to the flared fianges during thebrazing assembly operation. Since the flanges engage and are secured tothe bearing housing 33 at points spaced relatively widely lengthwisethereof, they provide a rigid and accurately aligned support for thebearin housing. Bearings 33a are provided in the housing for journallingshaft 78.

In order accurately to locate the three sheet metal sleeves 23, 24 and25 prior to and during assembly, the lower plate member is made of asize to enter the upper end of the outer sleeve 23. Thus, the sleeve 23will be accurately positioned radially and the abutment of its upperedge against the upper plate 26 will locate the end member accurately inan axial direction with respect to the sleeves. The lower plate member27 is also formed with a pair of radially-spaced annular beads orprotrusions 35 and 36 which engage the ends of the intermediate sleeve24 and inner sleeve 25. These sleeves are thus accurately positionedwith respect to the upper end memher and are held accurately in positionduring the assembly and brazing operations.

The lower plate member is formed by a series of stacked annular sheetmetal plates 37, 38, 33, 40 and 41. The outermost plate 37 is formedwith a series of spaced openings therein through which the pins 15project. The next adjacent plate 38 has a larger central opening thanthe plate 37 so that its inner edge is spaced radially outward from theinner edge of plate 37 as shown. The plate 39 completely overlies theplate 37 and has a smaller opening therethrough than the plate 38 sothat its inner edge extends radially inwardly from the inner edge ofplate 38. In this way an annular groove 42 is formed between the plates37 and 39 to receive a snap ring as described more fully hereinafter.

The plate 41 abuts at its outer edge against the intermediate sleeve 24and extends under the lower edge of the inner sleeve as shown. Plate 40is preferably also of the same external diameter as the plate 41 andabuts at its outer edge against the intermediate sleeve 24. The plate 41has a smaller central opening therethrough than the plate 40 so that itprojects inwardly beyond the inner edge of the plate 49 for a purpose toappear more fully hereinafter.

The lower edges of the sleeves 23, 24 and 25 are accurately locatedrelative to the bottom closure member in a manner similar to that inwhich the upper edges of the sleeves are located. Thus, the annularplates 38 and 39 fit within the lower end of the outer sleeve 23 and theplate 39 is formed with an annular bead 43 which engages the outersurface of the intermediate sleeve 24. The upper plate 41 and the plate40 fit within the intermediate sleeve 24 and the sleeve 41 is formedadjacent to its inner edge with an annular bead 44 which engages andlocates the outer surface of the inner sleeve 25. Preferably, thesleeves 24 and 25 are also formed with beads 45 which support and locatean annular ring 46 lying between these two sleeves and spaced above thebottom member of the crankcase assembly.

In order to support a motor in the crankcase assembly, a sleeve 47 issecured to the upper plate 26 of the top member and is accuratelylocated thereon by an annular bead 48 projecting upwardly from the topmember. The

sleeve 47 is formed with a series of circumferentially spaced inwardlyextending corrugations 49 which are adapted to receive and support amotor stator as described more fully hereinafter. Preferably, each ofthe corrugations is formed adjacent to its lower end with a punched outtongue 51 against which the lower edge of the motor stator will seat toposition the motor stator accurately in the crankcase assembly. Thesleeves 23, 24 and 25 are provided at one or more points around theircircumference with radially aligned openings, the opening in the outersleeve 23 being slightly larger than that in the intermediate sleeve 24,and the opening in the inner sleeve 25 being smaller than the opening inthe sleeve 24. The openings in the outer and intermediate sleeves areadapted to receive tubular valve housings 52. Normally, for a fourcylinder compressor there will be four such valve housings whose axialpositions with respect to the sleeves are staggered as indicated in FIG.2. Each valve housing has an outer ring portion 53 of maximum diameterwhich is slightly larger than the diameter of the opening in the outersleeve 23. This ring portion is joined by a tubular body portion havinga maximum diameter portion 54 joining the ring portion and an innerminimum diameter portion 55 at the inner end thereof. The inner edge ofthe valve body is stepped as shown at 56 to fit into the opening in theintermediate sleeve 24 and to define a shoulder abutting against theouter surface of that sleeve. The outer ring portion 53 of the valvebody is formed with an annular internal groove 57 to receive a retainingring as described more fully hereinafter.

The space between the outer sleeve and the intermedi ate sleeveconstitutes an annular discharge gas chamber into which compressed gaspasses from the valve. For this purpose the valve housing is formed withone or more openings 58 communicating with the discharge space. In orderto mufile the noise of the discharge gas, an annular corrugatedperforated sheet metal strip 59 is positioned in the space between theouter and intermediate sleeves and is secured thereto by brazing duringthe assembly operation. As the gas flows through the discharge chamber 4and through the perforations in the strip 59, its flow will be muflled.

The openings in the inner sleeve 25 receive annular members 61 which fitclosely in the openings and which are preferably provided with outerannular flanges 62 to engage the outer surface of the inner sleeve asshown.

It will be observed that all parts of the crankcase assembly as so fardescribed with the possible exception of the bearing housing 33, thevalve housing 52 and the sleeve 61 are formed of sheet metal. All of theparts are relatively simple ones which can be stamped out of standardsheet steel and which can be assembled and held in proper positionrelative to each other by simple jigging. The hearing housing 33, valvehousing 52 and sleeve 61 may be screw machine parts or could, ifdesired, be formed of powdered metal or in any other desired way. Theseparts can easily be inserted in the openings provided for them and willbe accurately located and retained by the shoulders formed thereon. Withthe several parts assembled as shown in FIG. 2 and held in assembledrelationship by suitable jigs or fixtures, the entire assembly may beplaced in a hydrogen brazing furnace and the parts may be rigidly brazedtogether. It will be understood that the portions of the severaldifferent sheet metal parts where they meet may be preeoated withsuitable brazing and fluxing compounds so that when the assembly isheated to a proper brazing temperature, normally about 2050 F., all ofthe parts will be rigidly and permanently secured together.

Once the crankcase assembly is completed as described above, theremaining parts necessary to complete the compressor may easily beassembled therewith. A bearing is provided for the lower end of thecompressor crankshaft. As shown in FIG. 1, the bearing comprises acup-shaped bearing housing member 63 formed adjacent to its upper edgewith a projecting flange. T he lower part of the cupshaped member ispreferably formed with an opening 64 which constitutes the inlet of theimpeller or pump means which are defined within the crankshaft to bereferred to hereinafter. The bearing housing 63 is secured to asupporting plate defined by two annular plates 65 and 66 whose inneredges are flared outwardly in substantially the same manner as the inneredges of the plates 26 and 27. The bearing housing 63 fits into theopening defined by the flared inner edges of plates 65 and 66, with theshoulder at the upper end thereof abutting against the flared upper edgeof the plate 65 accurately to locate the bearing housing in an axialdirection. The bearing housing is preferably secured to the flared edgesof the plates 65 and 66 by brazed in the same manner that the sheetmetal parts of the crankcase assembly are secured together.

To assemble the bearing housing 63 in the crankcase, the plates 65 and66 are inserted through the central opening of the bottom or outer plate37 with the upper face of plate 65 abutting the lower surface of theplate 41 and with the outer edges of the plates 65 and 66 engaging theinner edges of the plates 40 and 39, respectively. In this way, thebearing plates 65 and 66 and the bearing housing 63 are accuratelylocated in the crankcase assembly. Bearing 63a is press fit or otherwiseSecured in housing 63. To secure the bearing in place, a snap ring 67 isinserted in the groove 42 as shown in FIG. 1 and engages the lowersurface of the plate 66 to secure it and the entire lower bearingassembly accurately in position in the crankcase.

A cylinder sleeve and valve assembly as more particularly described andclaimed in my copending application Ser. No. 587,006 filed Oct. 17,1966, and indicated generally at 68 together with associated piston andconnecting rod may then be inserted radially into each of the valvecasings 52 as shown in FIG. 1. Each cylinder sleeve and valve assemblycomprises a cylinder 69 having a stepped outer surface at one end to fitwithin one of the sleeves 61 and having an outwardly-extending flange 71at its other end to fit within the small diameter portion 55 of thevalve casing. A piston 72 is slidable in each of the cylinders and isconnected through a wrist pin 73 to a connecting rod 74 which extendsgenerally radially into the crankcase. At its inner end each connectingrod is formed with a circular bearing portion 75 adapted to engage withan eccentric portion on the crankshaft.

A valve assembly indicated generally at 76 is secured to the flange 71of the cylinder and carries various valve parts as described more fullyin my copending application referred to above. After the valve assemblyand cylinder and piston have been inserted into the valve casing 52,they are retained in place by a snap ring or similar fastener 77 fittinginto the annular groove 57 in the valve casing.

A crankshaft 78 extends through the bearings 33a and into the bearing63a and is provided intermediate its ends with an eccentric crankportion '79 and closely adjacent thereto with a counter-weight portion81. The crankshaft is formed with a lower bearing portion 82 fittinginto the lower bearing 63a, with an intermediate bearing portion 83fitting into the bearing 33a, and with an upper shaft portion 84extending upwardly through the motor supporting sleeve 47. With theseveral cylinder sleeve and valve assemblies and associated pistons inplace, the crankshaft may be inserted from the bot tom of the crankcase(with the lower bearing housing 63 removed) by passing the shaft portion84 and crankshaft bearing portion 83 through the Connecting rod bearings75 and then through the upper bearing housing 33 until the crankshaft isin the position shown in FIG. 1. Thereafter, the lower bearing housing63 may be inserted over the bearing portion 82 at the lower end of thecrankshaft and can be secured in place by inserting the snap ring 67.

As is more particularly disclosed and claimed in my Patent No.3,253,776, the crankshaft is provided with a plurality ofvertically-disposed passageways which are offset from the axis ofrotation of the shaft and which communicate with the opening 64 in thelower bearing housing 63 by a transversely-disposed passage 86. Asshown, the passage 86 is open at its opposite ends to lubricate thebearing 63a. The crank or eccentric 79 of the crankshaft is providedwith passages 87 communicating with vertically-disposed passages (notshown). The passages 87 open at the surface of the crank portion '79 toprovide relatively high pressure and relatively low pressure lubricationof the several connecting rod bearings 75. Passages are provided in thecrankshaft communicating with the upright pass-age 85 and opening at theexterior of the bearing portion 83 for lubricating the 0 upper bearing33a. A refrigerant vapor vent passage 89 may be provided at the upperend of the crankshaft bearing portion 83 to vent any vapor which getsinto the passage 85.

The crankshaft 78 is driven by a motor which comprises an annnularstator structure 91 of an external diameter to fit closely within thecorrugations 49 and with its lower edge engaging the tongues 51 to limitmovement of the stator into the sleeve 47 and to position the statoraccurately. An annular rotor 92 is rotatable within the stator and fitsover the shaft portion 84. The rotor may be secured to the shaft 84 bykeying or in any other suitable manner. After the stator and rotor areinstalled, a motor shroud or cover 93 may be placed over the motor withits lower edges telescoping over and secured to the upper end of thesleeve 47. The cover 93 is formed in its top with a central opening 94.-through which the incoming suction gas may flow to flow over the motorand assist in cooling it and to then fiow through the openings 28 to thevalve assembly.

After the motor and compressor parts have been assembled with thecrankcase structure as described above, the entire assembly may beinserted in the lower shell 11 to be supported on the springs 16.Resilient rubber bumpers 95 are inserted in openings in the flange 29 ofplate 27 and bear against the sides of the lower shell 11 resiliently toposition and support the crankcase assembly. The assembly is thencompleted by adding the top cover part or shell 10 and making thenecessary wiring connections. Annular stop ring 98 in the shell 10 abutsflange 29 to limit upward movement of the compression mechanism withinthe outer housing.

The modified crankcase assembly of FIGS. 5 and 6 is much like that shownin FIGS. 1-3 and accordingly, like numerals are used to designate likeelements. Major changes are found in the construction of the upper andlower plate members and the valve housing. For added strength and tofacilitate fabrication, the upper and lower plate members each includerelatively thick plates 27 and 96, respectively, having annular recesses27a, 12 and c and 96a, b and 0, respectively, therein for receiving theupper and lower ends of sleeves 23, 24 and 25. The extended surface ofthe recesses cooperates with the exterior of the sleeves 23, 24, and 25to insure better sealing of the abutting surfaces. The recesses alsofunction to accurately locate and space the sleeves from one another.

Bearing housing 33 is supported in the central openings in plates 26 and27. Bearing liners 33a are provided in bearing housing 33 for journalingthe crankshaft.

The annular valve housings 53' are preferably formed from sheet metalinserted into openings in sleeves 23 and 24 and expanded into snugengagement with the wall means defining the openings in the sleeves. Thevalve housing 53 are then brazed or otherwise bonded to the sleeves toprovide a fluid-tight seal therebetween.

The motor support is defined by annular sleeve 47 secured to the top ofplate 26'. Annular recess 26a is provided in the plate 26' for locatingthe sleeve 47' on the plate 26 and for increasing the surface contact atthe bonded joint to enhance the seal between sleeve 47 and plate 26'.The ribs 49 for supporting the motor stator are formed from generallyU-shaped or V-shaped members secured to the interior of sleeve 47'.Tongues or projections 51 are struck from the ribs 49 or otherwiseformed on the ribs 49'. The lower edge of the motor stator abuts thetongues 51' to accurately position the rnotor stator within thecrankcase.

The rivets 99 or like fastening means are used to join the plates 26'and 27' during initial assembly. Subsequently plates 26' and 27 arejoined by brazing or chemical adhesive.

Secured to the bottom of plate 96 are a plurality of lower retainingmembers 101 formed from a plurality of plate segments connected to oneanother by fastenings 102. As shown, the retaining members are spacedapart. Defined within each retaining member is a recess 103 forreceiving a retaining ring to hold the lower bearing assembly in placein the crankcase.

While presently preferred embodiments of the invention have been shownand described in detail, it will be understood that this is for thepurpose of illustration only and is not to be taken as a definition ofthe scope of the invention, reference being had for this purpose to theappended claims.

What is claimed is:

1. In a refrigerant reciprocating compressor, a crankcase comprisingouter, intermediate and inner coaxial sheet metal sleeves of differentdiameters to define annular spaces between adjacent sleeves, annular topand bottom plate means joined to the opposite ends of the sleeves andsecuring them rigidly together, the sleeves being formed with radiallyaligned openings therethrough, a tubular valve housing secured in theopenings in the outer and intermediate sleeves, the valve housing andthe opening in the inner sleeve adapted to receive and support acylinder sleeve, the annular space between the inner and intermediatesleeves defining a suction gas inlet chamber and the valve housinghaving an opening therein communicating with the space between theintermediate and outer sleeves whereby said space serves as a dischargegas chamber.

2. The construction of claim 1 including a generally sinuous perforatedbathe in the discharge gas chamber extending axially of the adjacentsleeves to mufile the discharge gas.

3. The construction of claim 1 in which the top and bottom plate meanshave locater means formed on their inner faces against which the ends ofthe intermediate and inner sleeves seat accurately to position thesleeves.

4. The construction of claim 3 in which the locater means compriserecesses in the inner faces of the top and bottom plate means.

5. The construction of claim 1 in which the bottom plate means is formedof at least two annular plates spaced at their inner edges to define anannular recess adjacent to the innermost plate to receive a bearingsupporting plate and an annular groove adjacent to the outermost plateto receive a snap ring.

6. The construction of claim 1 in which the bottom plate means is formedof at least four annular plates secured together face-to-face, thesecond plate from the outer end of the crankcase having a largerinternal opening than the immediately adjacent plates to definetherewith an internally opening annular groove and the innermost platehaving a smaller internal opening than the plate immediately adjacentthereto, a bearing .and an annular bearing supporting plate secured tothe bearing and fitting face-to-face against the inner edge of theinnermost plate and fitting within the plate next adjacent thereto, anda snap ring fitting in said groove to secure the bearing supportingplate in place.

7. The construction of claim 6 in which the bearing supporting platecomprises two annular plates secured together face-to-face with theirinner edges flared in oplll posite directions, and the bearing fits inthe central openings in the plates and is secured to the flared inneredges thereof.

8. The construction of claim 1 in which the top plate means comprisestwo annular plates secured together in face-to-face relationship, theinner edge of at least one of said plates being flared, and a tubularbearing fitting in the central openings in the plates and secured to theflared inner edge.

9. The construction of claim 1 including sleeve means secured to the topplate means and projecting outward therefrom and adapted to receive andsupport the stator of a motor.

10. The construction of claim 8 in which the last named sleeve means isformed with a series of inwardly projecting axially extending ribsclosely to receive the stator and having stop means thereon to limitmovement of the stator into the sleeve means.

11. The construction of claim 9 including a plurality .of ribs formedfrom a single corrugated member, the ribs having stop means thereon foraccurately positioning a motor stator within the sleeve means.

12. The construction of claim 1 including an annular sleeve member inthe opening in the inner sleeve, the annular sleeve member being coaxialwith an associated valve housing, the sleeve member and the valvehousing cooperating to receive a cylinder sleeve and valve assemblytherein.

References Cited UNITED STATES PATENTS ROBERT M. WALKER, PrimaryExaminer.

1. IN A REFRIGERANT RECIPROCATING COMPRESSOR, A CRANKCASE COMPRISINGOUTER, INTERMEDIATE AND INNER COAXIAL SHEET METAL SLEEVES OF DIFFERENTDIAMETERS TO DEFINE ANNULAR SPACES BETWEEN ADJACENT SLEEVES, ANNULAR TOPAND BOTTOM PLATE MEANS JOINED TO THE OPPOSITE ENDS OF THE SLEEVES ANDSECURING THEM RIGIDLY TOGETHER, THE SLEEVES BEING FORMED WITH RADIALLYALIGNED OPENINGS THERETHROUGH, A TUBULAR VALVE HOUSING SECURED IN THEOPENINGS IN THE OUTER AND INTERMEDIATE SLEEVES, THE VALVE HOUSING ANDTHE OPENING IN THE INNER SLEEVE ADAPTED TO RECEIVE AND SUPPORT A CYLIN-